With the 2016 Olympics looming, the role of transgender athletes – in particular, trans women – in sports has been drawing increasing attention. But do trans women really have an edge?
To date, no openly transgender athlete has competed in the Olympics. But that is bound to change; since 2004, Olympic rules have permitted trans women to compete in athletics if they are two years removed from gender-reassignment surgery.
It was a decision based in part on a Dutch study in the European Journal of Endocrinology, which found that within a year after gender-reassignment surgery, trans women had testosterone and haemoglobin levels no higher than their female-born compatriots. That’s important because high testosterone is associated with masculine levels of muscle mass and strength, while high haemoglobin is associated with greater aerobic capacity and therefore speed.
Thus, to be on the safe side, the Olympic rules committee then decided to double that waiting period.
But whatever their current hormone levels and blood profiles, do these women’s prior lives as males give them an unfair advantage when competing against athletes who were born female? After all, men’s track records are about 10% faster than women’s, so it wouldn’t take much of a carryover advantage to give them a competitive edge.
For years, nobody knew. Then Joanna Harper, a medical physicist from Portland, Oregon, got to wondering if there was a way to test it.
Harper herself is a trans woman and a frequent, serious road racer. Like many trans women, she didn’t make the transition until middle age. That made it hard for her to compare her best performances as a young man and an older woman.
In 2003, shortly before her transition, for example, she was a 46-year-old male with a 10-kilometre time of 37:10. Two years later she ran 42:01 on the same course as a 48-year-old female. That’s an 11.5% slowdown — almost exactly what you’d expect from the male-to-female transition plus two years of ageing.
Nor had Harper become lazy. “I wasn’t about to let a little thing like a sex change cut into my training and racing,” she quips.
But Harper realised she could compare her pre- and post-transition times by using a set of popular “age-grading” tables compiled by British statistician Howard Grubb.
These tables rate performances on the basis of the percentage of world-record pace you run for your age and gender.
Harper contacted seven other trans women (ranging in age from upper 20s to lower 50s at the time of transition) who were willing to share their experiences.
Some were national-class talents, others mid-pack competitors, but in research published last year in the Journal of Sporting Cultures and Identities, she found that, like hers, their average age-and-gender-graded performances barely budged after their transitions.
Before changing genders these runners (including Harper) had, on average, performed at the 68.7% level. Afterwards, as slightly older women, they performed at the 68.5% level.
The one exception had cut 50 minutes off her marathon time, from 3:48:55 as a 19-year-old male to 2:59:10 as a 31-year-old female. But she’d also doubled her training and lost nine kilograms. “She got serious,” Harper says. “Not surprisingly, she got faster.”>
It’s an important find, other researchers say, though in many ways only the beginning.
Geoffroy Berthelot, a specialist in informatics and algorithmics at the National Institute of Sport, Expertise, and Performance, Paris, France, calls Harper’s study a “great first step”, but cautions that her small group of runners didn’t include any international-level elite athletes.
At that level, he says, transgender athletes might have small advantages Harper’s study wasn’t able to address.
Yannis Pitsiladis, a professor of sports and exercise science at the University of Brighton in the UK, agrees. “What’s required are studies where we could follow individuals from male-to-female and female-to-male as they make the transition,” he says.
Not only would such studies focus on performance, but they would examine the effect of gender transition on such factors as gene expression, protein production and metabolism.
Richard A Lovett
Richard A Lovett is a Portland, Oregon-based science writer and science fiction author. He is a frequent contributor to Cosmos.
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